Polyampholyte poly[2-(dimethylamino)ethyl methacrylate]-star-poly(methacrylic acid) star copolymers as colloidal drug carriers

Abstract

Herein, polyampholyte star copolymers have been prepared via a two-step reversible addition-fragmentation chain transfer (RAFT) polymerization combined with disstilation presipitation polymerization (DPP). We have used arm-first approch where poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA) arms have been synthesized in three different molecular weights. Then, PDMAEMA arms have been used as macroRAFT agent in DPP of MAA to prepare crosslinked core by N,N'-methylenebisacrylamide (MBA). Nuclear magnetic resonance (1H NMR), differential scanning calorimetry (DSC), and gel permeation chromatography (GPC) have been used to confirm the accuracy of the synthesized star polyampholytes. The effect of pH on the self-assembly behavior of PDMAEMA-star-PMAA star copolymers has been investigated by dynamic light scattering (DLS) and field emission scanning electron microscopy (FE-SEM). Also the cloud point (turbididity behavior) of the star polyampholytes has been investigated by UV–vis spectroscopy. Result indicated that, morphologies containing spherical, rod-shaped, and worm-like structures with different sizes have been obtained by chenging pH value. Also, doxorobicin (DOX) release behavior has been exmined for star polyampholytes at disparate pH values. Results showed that release amount was higher at pH = 1 than that at pH = 7 with high amount of DOX release.